BeyondSpring Shares Phase 2 Results of Pembrolizumab and Plinabulin/Docetaxel in Metastatic NSCLC at ESMO 2024

Median PFS at 8.63 months and Disease Control Rate of 89.5% in Previously Treated NSCLC Patients after Progression on PD-1/L1 Monotherapy or in Combination with Platinum Doublet Chemotherapy

FLORHAM PARK, N.J., Sept. 16, 2024 -- BeyondSpring Inc., a clinical-stage biopharmaceutical company focused on innovative cancer treatments, has revealed interim phase 2 data from the 303 Study. This study is evaluating second and third-line treatments for non-small cell lung cancer (NSCLC) after progression on first-line PD-1/L1 inhibitors, with or without chemotherapy. The study is backed by Merck & Co., Inc’s Investigator Studies Program and was presented at the European Society for Medical Oncology (ESMO) Congress 2024 in Barcelona, Spain.

For patients with 2L/3L NSCLC without targetable alterations who progress after initial treatment with immune checkpoint inhibitors (ICI) and chemotherapy, docetaxel remains the standard care. The typical response rate for these patients is an overall response rate (ORR) of 12.8% and median progression-free survival (PFS) of 3.7 months, according to TROPION Lung-01 phase 3 studies. For metastatic NSCLC resistant to previous PD-1/L1 therapy, PD-L1 and CTLA-4 inhibition, even in combination with radiotherapy, provides limited benefits with an ORR of approximately 11.5%.

The investigator-initiated, phase 2 study (KeyPelms-004 or 303 Study) is assessing the efficacy and safety of a combination of pembrolizumab, plinabulin, and docetaxel. Sixty-eight percent of the study participants are male, and thirty-two percent are female, with a median age of 66.4 years. Additionally, nearly 58% of the participants are current or former smokers. Histologically, 57.9% have non-squamous cell carcinoma, and 42.1% have squamous cell carcinoma. The study is ongoing at Peking Union Medical College Hospital in Beijing, China, led by Dr. Mengzhao Wang.

As of April 29, 2024, 29 patients had been enrolled in the study, and 19 were evaluable for data analysis. All had experienced disease progression after initial ICI treatment. The report reveals promising efficacy results from this interim analysis. The primary endpoint, confirmed ORR, stands at 21.1%. Secondary endpoints show a median PFS of 8.63 months, with 6-month and 12-month PFS rates at 67.1% and 49.2%, respectively. Median overall survival (OS) has yet to be reached, and the median duration of response (DoR) is 11.40 months. The disease control rate, defined as partial response or stable disease for more than four months, is 89.5%.

In terms of safety, the combination of treatments was generally well tolerated. More than half of the patients (52.6%) experienced grade 3 or higher treatment-related adverse effects, but there were no treatment-related deaths.

Dr. Mengzhao Wang commented on the study, emphasizing the role of plinabulin in dendritic cell maturation and T cell activation. This mechanism potentially overcomes acquired ICI resistance, which is crucial for patients facing this severe unmet medical need. The study's early data suggests a significant improvement in median PFS compared to historical controls, which is a meaningful development in treating this challenging condition.

The 303 Study is designed to enroll a total of 47 patients and is funded by Merck’s Investigator Studies Program, which also provides the study drug. BeyondSpring continues to focus on developing pioneering therapies to improve outcomes for patients with significant unmet medical needs.